Pressure intensifier for windshield wipers

ABSTRACT

A pressure-intensifying attachment for windshield wipers has a base plate, in the shape of a generally trapezoidal strip, which clamps onto a wiper arm and carries on its exposed surface a set of transverse wind-catching ribs progressively increasing in height from the narrow end to the wide end of the strip. The clamping unit comprises a bar of substantially triangular crosssection, integrally joined along one edge to the rear surface of the plate, bearing with the apex of its triangular profile upon the engaged wiper arm which is bracketed by upstanding flanges of a guide rail rigid with that rear surface.

United States Patent Friihlich 1451 Aug. 22, 1972 [54] PRESSUREINTENSIFIER FOR 3,320,628 5/ 1967 Bacher et al l 5/250.42 X

HI 2 WINDS l rl i B d 9 FOREIGN PATENTS OR APPLICATIONS F t v [7 1Invent zf g i 8 ram 1,105,704 3/1968 Great Brltam ..15/250.42

[ Filedi g- 1970 Primary ExaminerP. Feldman [21] AppL NO; 61,232Attorney-Karl F. Ross [57] ABSTRACT [30] Forelgn Apphcatlon Pnomy Data Apressure-intensifying attachment for windshield Sept. 30, 1969 Germany..G 69 38 113.1 wipers has a base plate, in the shape of a generallytrapezoidal strip, which clamps onto a wiper arm and 52 us. c1...1s/250.2, 15/250.35, 15 250.42 carries on its exposed Surface a set oftransverse wind- 51 Int. Cl. ..B60S 1/32 catching ribs pregressivelxincreasing in height from [58] Field of Search....15/250, 250.2, 250.35,250.42 the herrewvehd to t Wide end of e p; T

clampmg umt comprises a bar of substanually triangud lar cross-section,integrally joined along one edge to [56] References Cite the rearsurface of the plate, bearing with the apex of UNITED STATES PATENTS itstriangular profile upon the engaged wiper arm which is bracketed byupstanding flanges of a guide Nem1c X that rear Surface. 3,037,2336/1962 Peras et al. 15/250.42 3,317,946 5/ 1967 Anderson l5/250.42 7Claims, 3 Drawing Figures PATENTEDMIBZZIBYZ 3.685.086

Fig.7 v I 2-8.. a, 11'1 i lzr Fig.3 0

N J l 5 KW v/ J KARL FRBHLICH #WQnfor:

by mar Tm Attorney PRESSURE INTENSIFIER FOR WINDSHIELD WIPERS My presentinvention relates to a pressure intensifier for windshield wipers,designed to avoid the floating of the windshield wiper on the water filmformed on the windshield in the rain.

A known pressure intensifier consists of a flat or slightly inwardlycurved wind-catching plate broadening from one end to the other andhaving a clamp at its lower side which clasps the wiper arm by pinching.This known pressure intensifier satisfies the needs of the driver onlyinsufficiently. On the one hand the pressure obtained by this attachmentis not sufiicient for urging the windshield wipers firmly enough againstthe windshield. The primary reason for this is the fact that the angleformed by the wind-catching plate and the horizontal due to the slantingof the windshield is too small for an effective utilization of thedynamic wind pressure obtaining at high speed. Another disadvantage ofthe known attachment is the fact that it is not possible to use ituniversally for all types of wipers, so that the pressure intensifiersmust be manufactured with holding devices corresponding to the differentwiper types.

Another known pressure intensifier consists primarily of several wingsfixed with an angle of inclination of about 45 one by one directly onthe holding device. In this case the wings are situated substantiallyperpendicularly to the longitudinal axis of the vehicle, so that a goodintensification of pressure is achieved, but because of its excessivesize it cannot be used for vehicles with disappearing wipers.

The object of the present invention is the creation of a smallerpressure intensifier which with sufficient gripping force may be fixedeasily on every type of wiper and which guarantees an adequateintensification of pressure in all operational and weather conditions.In contradistinction to the conventional pressure intensifier describedabove, the wind-catching surface of the elongate base plate of myimproved attachment has transverse ribs shaped like a swallow-tail.These transverse ribs form wind-catching areas directed into the drivingwind, thereby fully utilizing the force of that wind, so that a highwiper pressure is realized. Furthermore, the swallow-tail form of thetransverse ribs effects a constant and uninterrupted flow of the air.There are no dead areas where snow or water could deposit for a longertime; snow amassing during hours of parking will immediately be seizedand taken away by the driving wind when the car is started.

Advantageously the transverse ribs increase in height from the small endto the broad end of the windcatching plate, whereby even on veryslanting Windshields or wiper arms full effectiveness of the upper ribsis also insured.

For fastening the pressure intensifier on the wiper arm I prefer to usea U-profile with a throughgoing or interrupted side flange as a guiderail for the wiper arm in co-operation with a clamping bar of nearlytriangular cross-section which overhangs the rail over the clampingarea. In this case the position of the clamping bar relative to theguide rail is advantageously such that as seen in cross-section thebearing ridge formed by the apex of the triangle is shifted toward theoutside,

way, pressure intensifiers of one given size may be used for everycurrent type of wiper with a sufficiently strong hold on the wiper arm.In order to avoid the exertion of torsion by the pressure intensifier onthe wiper arm, an additional holding lug may be fixed to the clampingbar at its attached edge. Furthermore, the lateral edge on the open sideof the clamp may be beveled off at the inside in order to facilitate thefastening of the attachment on the wiper arm.

An embodiment of my invention has been illustrated in'the accompanyingdrawing in which:

FIG. I shows a top view of a pressure intensifier according to theinvention;

FIG. 2 shows a side view of the pressure intensifier of FIG. 1; and

FIG. 3 shows a cross-sectional view taken on the line IIIIII of FIG. 2.

In the drawing I have shown an elongate windcatching plate 1 of apressure intensifier according to the invention, which is fixed to awiper arm 9 by a clamping device generally designated 2. Thewindcatching plate, here shown as a flat strip of generally trapezoidalshape, broadens from one end la to the other end lb.

According to the invention, and as best seen in FIG. 1, the base plate 1has its exposed surface provided with transverse ribs 3 of swallow-tailshape which moreover (see FIG. 2) progressively increase in height fromthe small end la toward the broad end lb. At the side directed towardthe driving wind, i.e., forwardly with reference to the motion of thevehicle bearing the wiper, the ribs 3 are rounded off at the edgesconnecting them with the wind-catching plate, whereby accumulation ofsnow and ice is avoided.

For fastening the attachment to the wiper arm 9 there is provided aU-profile 5 forming a guide rail with a gap in one of its flanges toform a pair of spaced-apart retaining ledges 4, this rail confronting aclamping bar 6 of nearly triangular cross-section fixed at one side tothe wind-catching plate 1 and overhanging the guide rail 5 along theclamping area. The bearing edge 6a of the clamping bar 6 is shiftedtoward the outside, i.e., offset in the direction of the outer edge ofthe bar with reference to the longitudinal plane of symmetry 7 of therail 5 indicated in FIG. 3.

Between the clamping bar 6 and the guide rail 5 there is provided aholding lug 8 preventing a twisting of the wiper arm 9 by theunsymmetrical bearing pressure of ridge 6a, the lug overlying the innerflange'4of the rail and projecting past it to engage the wiper arm. Inorder to facilitate the mounting of the attachment on the wiper arm, theinner edges 4a of the holding ledges 4 are beveled.

The complete pressure intensifier may be manufactured all in one piece,in which case the rail flanges are situated directly on the base plate1.

I claim:

1. A pressure-intensifying attachment for a windshield wiper, comprisingand elongate base plate of generally trapezoidal shape with a wider endand a narrower end, clamping means on one surface of said plate forfastening it to a wiper arm, and a set of transverse ribs on the exposedopposite surface of said plate, said ribs being of swallow-tailconfiguration.

2. An attachment as defined in claim 1 wherein said ribs increaseprogressively in height from said narrower end to said wider end.

3. An attachment as defined in claim 1 wherein said ribs are rounded attheir junctions with said plate.

4. An attachment as defined in claim 1 wherein said clamping meanscomprises a guide rail extending longitudinally on said one surface,said rail having upstanding flanges bracketing said wiper arm', and apressure bar integral with said plate overhanging said rail, said barbeing of generally triangular cross-section with a bearing ridge at theapex of the triangle confronting

1. A pressure-intensifying attachment for a windshield wiper, comprisingand elongate base plate of generally trapezoidal shape with a wider endand a narrower end, clamping means on one surface of said plate forfastening it to a wiper arm, and a set of transverse ribs on the exposedopposite surface of said plate, said ribs being of swallow-tailconfiguration.
 2. An attachment as defined in claim 1 wherein said ribsincrease progressively in height from said narrower end to said widerend.
 3. An attachment as defined in claim 1 wherein said Ribs arerounded at their junctions with said plate.
 4. An attachment as definedin claim 1 wherein said clamping means comprises a guide rail extendinglongitudinally on said one surface, said rail having upstanding flangesbracketing said wiper arm, and a pressure bar integral with said plateoverhanging said rail, said bar being of generally triangularcross-section with a bearing ridge at the apex of the triangleconfronting said plate.
 5. An attachment as defined in claim 4 whereinsaid bearing ridge is offset from the centerline of said rail toward thefree edge of said bar.
 6. An attachment as defined in claim 5 whereinsaid bar is provided at its attached edge with a holding lug overlyingand projecting beyond the adjoining flange of said rail.
 7. Anattachment as defined in claim 4 wherein the flange of said rail next tothe free edge of said bar is inwardly beveled.